Sinus of Valsalva aneurysm (SVA) unassociated with ventricular septal defect does not produce symptoms of cardiac dysfunction until the wall of the SVA ruptures or the aneurysm itself obstructs right ventricular (RV) outflow. If rupture occurs, usually symptoms appear abruptly and congestive heart failure progresses rapidly thereafter. Obstruction to RV outflow by bulging of the SVA into the RV outflow tract has been demonstrated hemodynamically in only 2, possibly 3, patients. The patient in this report is unique because the degree of RV outflow tract obstruction by a SVA was observed to increase with time and symptoms of cardiac dysfunction never occurred despite rupture of the wall of the SVA.